Advances in research of the artificial cultivation of Ophiocordyceps sinensis in China

Biological Characteristics, Artificial Domestication Conditions Optimization, and Bioactive Components of Beauveria caledonica

In this study, one strain of Beauveria caledonica was isolated from wild fruiting bodies collected from Guizhou Province, China, and its species identification, biological characteristics, domestication, and cultivation methods were studied along with polysaccharide and adenosine content analysis. The mycelia were identified by ITS sequencing, and the fruiting bodies of B. caledonica were domestically cultivated for the first time using wheat and rice as basic cultivation media. The carbon sources, nitrogen sources, cultivation temperatures, and pH for mycelial growth were optimized through single-factor experiments and response surface methodology (RSM) experiments. The polysaccharide content was detected by the phenol-sulfuric acid method, and the adenosine content was measured by high-performance liquid chromatography (HPLC). The results confirmed that the identified mycelia were B. caledonica. The optimum medium for solid culture was 25.8 g/L glycerol, 10.9 g/L yeast extract, 1 g/L MgSO4·7H2O, 1 g/L KH2PO4, 10 mg/L vitamin B1, and 20 g/L agar; the optimum pH was 6.5, and the optimum culture temperature was 25 °C. The optimal liquid culture medium was 26.2 g/L glycerol, 11.1 g/L yeast extract, 1 g/L MgSO4·7H2O, 1 g/L KH2PO4, and 10 mg/L vitamin B1; the mycelia grew well at pH 6.6 and 25 °C. The average biological efficiencies of fruiting bodies on wheat and rice as culture media were 1.880% and 2.115%, respectively; the polysaccharide contents of fruiting bodies on the two media were 6.635% and 9.264%, respectively, while the adenosine contents were 0.145% and 0.150%, respectively. This study provides a valuable reference for further artificial cultivation and utilization of B. caledonica by investigating its biological characteristics, cultivation conditions for artificial domestication, and polysaccharide and adenosine contents in cultivated fruiting bodies.

Origin traceability of Cordyceps sinensis based on trace elements and stable isotope fingerprints

Cordyceps sinensis is a kind of valuable Chinese herbal medicine, and its quality and price depend on the place of origin. Building a traceability system for Cordyceps sinensis products is an effective way to protect Cordyceps sinensis geographical indication products and consumers. In this study, concentrations of 45 trace elements and stable C, N, and Pb isotopes were used to distinguish Cordyceps sinensis samples from different habitats and different varieties (natural and artificial). The results showed that there were significant differences in the isotope compositions of N and Pb and trace elements contents in the Cordyceps sinensis samples from different sources. Stepwise discriminant analysis was used to select effective traceability indicators, and three discriminant models were successfully established. A combination of Co, Sr, Cu, Tl, and Zr indexes was selected to distinguish the naturally grown samples from the artificially cultivated ones, with an overall cross-validation correctness rate of 90.0 %; while a combination of As, Cu, Rb, Tl, W, and Zr indexes was adopted to distinguish the naturally grown samples from different regions, with a corresponding 100.0 % overall cross-validation correctness rate. To simultaneously distinguish samples between natural and artificial and between different regions, a combination of As, Cu, Rb, Tl, U, W, and δ15N indexes was employed, with an overall cross-validation correctness rate of 89.3 %.

Histopathological observations and comparative transcriptome analysis of Ophiocordyceps sinensis infection of Hepialus xiaojinensis in the early stage

Hepialus xiaojinensis is a Lepidopteran insect and one of the hosts for the artificial cultivation of Cordyceps. Ophiocordyceps sinensis can infect and coexist with H. xiaojinensis larvae for a long time. Little studies focused on the interaction process through its early infection stage. In this research, we particularly study the interaction of infected and uninfected larvae in the 3rd (OS-3, CK-3) and 4th (OS-4, CK-4) instars. O. sinensis was distributed within the larvae and accompanied by pathological changes in some tissue structures. In response to O. sinensis infection, OS-3 enhanced the antioxidant defense ability, while OS-4 decreased. The transcriptome analysis showed that OS-3 resisted the invasion of O. sinensis by the immune and nervous systems. Correspondingly, OS-4 reduced immune response and utilized more energy for growth and development. This study provides a comprehensive resource for analyzing the mechanism of H. xiaojinensis and O. sinensis interaction.

Systematic analyses with genomic and metabolomic insights reveal a new species, Ophiocordyceps indica sp. nov. from treeline area of Indian Western Himalayan region

Ophiocordyceps is a species-rich genus in the order Hypocreales (Sordariomycetes, Ascomycota) depicting a fascinating relationship between microbes and insects. In the present study, a new species, Ophiocordyceps indica sp. nov., is discovered infecting lepidopteran larvae from tree line locations (2,202-2,653 m AMSL) of the Kullu District, Himachal Pradesh, Indian Western Himalayan region, using combinations of morphological and molecular phylogenetic analyses. A phylogeny for Ophiocordyceps based on a combined multigene (nrSSU, nrLSU, tef-1α, and RPB1) dataset is provided, and its taxonomic status within Ophiocordycipitaceae is briefly discussed. Its genome size (~59 Mb) revealed 94% genetic similarity with O. sinensis; however, it differs from other extant Ophiocordyceps species based on morphological characteristics, molecular phylogenetic relationships, and genetic distance. O. indica is identified as the second homothallic species in the family Ophiocordycipitaceae, after O. sinensis. The presence of targeted marker components, viz. nucleosides (2,303.25 μg/g), amino acids (6.15%), mannitol (10.13%), and biological activity data, suggests it to be a new potential source of nutraceutical importance. Data generated around this economically important species will expand our understanding regarding the diversity of Ophiocordyceps-like taxa from new locations, thus providing new research avenues.

Detection of the pathogenic fungus Cordyceps farinosa in the Thitarodes armoricanus soil-rearing environment based on nucleic acid targets

Cordyceps farinosa, an entomopathogenic fungus, infects and leads to high mortality of Thitarodes armoricanus larvae, which die soon after the infection of C. farinose, usually before the colonization of Ophiocordyceps sinensis owing to competitive inhibition and fruiting body formation. Therefore, monitoring C. farinosa in the O. sinensis cultivation environment is critical for minimizing the C. farinosa infection-induced losses. In this study, we initially designed a PCR primer pair (Tar-1F/Tar-1R) through open reading frame prediction and homology comparison of the C. farinosa genome sequence. This primer pair can detect both C. farinosa and Samsoniella hepiali. To further distinguish, primers (ITS5-172/ITS4-95) were then designed to selectively amplify the large ribosomal subunit sequences in the C. farinosa genome. All these primers were applied in combination for detection of C. farinosa in soil samples. The sensitivity reached a detection limit of 1 × 10⁶ spores/g soil. In addition, these primers can detect the presence of C. farinosa in dead T. armoricanus larval samples. This newly established rapid detection method provides important information for C. farinosa control during O. sinensis cultivation.

Fractional extraction and structural characterization of glycogen particles from the whole cultivated caterpillar fungus Ophiocordyceps sinensis

Ophiocordyceps sinensis (syn. Cordyceps sinensis) is a valuable medicinal fungus in traditional Chinese medicine, and one or more polysaccharides are the key constituents with important medical effects. Glycogen as a functional polysaccharide is widely identified in eukaryotes including fungi. However, there is no definitive report of glycogen presence in O. sinensis. In this study, we carefully fractionated polysaccharides from cultivated caterpillar fungus O. sinensis, which were then characterized via methods for glycogen analysis. According to the results, 1.03 ± 0.43 % of polysaccharides were quantified via amyloglucosidase digestion in the whole cultivated caterpillar fungus, which had a typical spherical shape under transmission electron microscope with an average peak radius of 37.63 ± 0.57 nm via size exclusion chromatography and an average chain length of 12.47 ± 0.94 degree of polymerization via fluorophore-assisted capillary electrophoresis. Taken together, this study confirmed that the polysaccharides extracted form O. sinensis were mostly glycogen.

Plant quercetin degradation by gut bacterium Raoultella terrigena of ghost moth Thitarodes xiaojinensis

Associated microbes of several herbivorous insects can improve insect fitness. However, the contribution of specific insect gut bacterium to plant toxin toxification for its host fitness remains scarce. Here, a gut bacterium Raoultella terrigena from the ghost moth Thitarodes xiaojinensis larvae was identified. This bacterium grew unhindered in the presence of Polygonum viviparum, which is a natural food for ghost moth larvae but showed significant growth inhibition and toxicity against Spodoptera litura. S. litura reared on artificial diets containing 5, 15 and 25% P. viviparum powder after 7 days coculture with R. terrigena were found to have shorter larval and pupal durations than on the diets containing P. viviparum powder but without R. terrigena coculture. HPLC analysis revealed that the content of quercetin in mineral medium containing 15% P. viviparum powder after 7 days coculture with R. terrigena was significantly decreased (79.48%) as compared with that in P. viviparum powder without R. terrigena coculture. In vitro fermentation further verified that R. terrigena could degrade 85.56% quercetin in Lucia-Bertani medium. S. litura reared on artificial diets containing 0.01, 0.05 and 0.1 mg/g quercetin after 48 h coculture with R. terrigena were also found to have shorter larval, prepupal and pupal durations, as well as higher average pupal weight and adult emergence rate than on the diets containing quercetin, but without R. terrigena coculture. In addition, R. terrigena was detected in the bud and root tissues of the sterilized P. viviparum, indicating that T. xiaojinensis larvae might acquire this bacterium through feeding. These results demonstrate that the gut bacteria contribute to the degradation of plant toxic molecules to improve the development of herbivorous insects and provide fundamental knowledge for developing effective methods for beneficial insect rearing and pest control.

Study of Pathogenesis Using Fluorescent Strain of Cordyceps farinosa Revealed Infection of Thitarodes armoricanus Larvae via Digestive Tract

Cordyceps farinosa is often utilized as a biocontrol agent because of its wide host range, strong lethality, and safety for mammals. Artificial rearing of Thitarodes armoricanus larvae is a prerequisite for the artificial cultivation of Chinese cordyceps, and C. farinosa is the most lethal pathogenic fungus during the rearing process. However, the infection process of C. farinosa is still unclear. In this study, we cloned the promoter of the C. farinosa glyceraldehyde 3-phosphate dehydrogenase gene, constructed the EGFP expression cassette, and integrated it into the C. farinosa genome via Agrobacterium transformation. We obtained a fluorescent strain for better observation of the infection process. Using two different inoculation methods of the fluorescent strain, we observed the traditional infection process through the body surface as well as through the digestive tract via feeding. Both infection modes can lead to larval death and mummification. Our findings demonstrated that during the artificial rearing of T. armoricanus, preventing C. farinosa pollution should be an important part of the disinfection of the rearing environment.

Cordyceps Improves Obesity and its Related Inflammation via Modulation of Enterococcus cecorum Abundance and Bile Acid Metabolism

Dysbiotic gut microbiota has been identified as a primary mediator of inherent inflammation that underlies the pathogenesis of obesity. Cordyceps comprises the larval body and the stroma of Cordyceps sinensis (BerK.) Sacc. parasiting on Hepialidae larvae of moths (H. pialusoberthur) with potent metabolic regulation functions. The underlying anti-obesity mechanisms, however, remain largely unknown. Here, we demonstrate that the water extract of Cordyceps attenuates glucose and lipid metabolism disorders and its associated inflammation in high-fat diet (HFD)-fed mice. 16S rRNA gene sequencing and microbiomic analysis showed that Cordyceps reduced the amounts of Enterococcus cecorum, a bile-salt hydrolase-producing microbe to regulate the metabolism of bile acids in the gut. Importantly, E. cecorum transplantation or liver-specific knockdown of farnesoid X receptor (FXR), a bile acid receptor, diminished the protective effect of Cordyceps against HFD-induced obesity. Together, our results shed light on the mechanisms that underlie the glucose- and lipid-lowering effects of Cordyceps and suggest that targeting intestinalE. cecorum or hepatic FXR are potential anti-obesity and anti-inflammation therapeutic avenues.

Enhancement of polysaccharides production using microparticle enhanced technology by Paraisaria dubia

Background

Polysaccharides are important active ingredients in Ophiocordyceps gracilis with many physiological functions. It can be obtained from the submerged fermentation by the anamorph (Paraisaria dubia) of Ophiocordyceps gracilis. However, it was found that the mycelial pellets of Paraisaria dubia were dense and increased in volume in the process of fermentation, and the center of the pellets was autolysis due to the lack of nutrient delivery, which extremely reduced the yield of polysaccharides. Therefore, it is necessary to excavate a fermentation strategy based on morphological regulation for Paraisaria dubia to promote polysaccharides accumulation.

Results

In this study, we developed a method for enhancing polysaccharides production by Paraisaria dubia using microparticle enhanced technology, talc microparticle as morphological inducer, and investigated the enhancement mechanisms by transcriptomics. The optimal size and dose of talc were found to be 2000 mesh and 15 g/L, which resulted in a high polysaccharides yield. It was found that the efficient synthesis of polysaccharides requires an appropriate mycelial morphology through morphological analysis of mycelial pellets. And, the polysaccharides synthesis was found to mainly rely on the ABC transporter-dependent pathway revealed by transcriptomics. This method was also showed excellent robustness in 5-L bioreactor, the maximum yields of intracellular polysaccharide and exopolysaccharides were 83.23 ± 1.4 and 518.50 ± 4.1 mg/L, respectively. And, the fermented polysaccharides were stable and showed excellent biological activity.

Conclusions

This study provides a feasible strategy for the efficient preparation of cordyceps polysaccharides via submerged fermentation with talc microparticles, which may also be applicable to similar macrofungi.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12934-021-01733-w.

Discovery of the signal pathways and major bioactive compounds responsible for the anti-hypoxia effect of Chinese cordyceps

ETHNOPHARMACOLOGICAL RELEVANCE

Hypoxia will cause an increase in the rate of fatigue and aging. Chinese cordyceps, a parasitic Thitarodes insect-Ophiocordyceps sinensis fungus complex in the Qinghai-Tibet Plateau, has long been used to ameliorate human conditions associated with aging and senescence, it is principally applied to treat fatigue, night sweating and other symptoms related to aging, and it may play the anti-aging and anti-fatigue effect by improving the body's hypoxia tolerance.

AIMS OF THE STUDY

The present study investigated the anti-hypoxia activity of Chinese cordyceps and explore the main corresponding signal pathways and bioactive compounds.

MATERIALS AND METHODS

In this study, network pharmacology analysis, molecular docking, cell and whole pharmacodynamic experiments were hired to study the major signal pathways and the bioactive compounds of Chinese cordyceps for anti-hypoxia activity.

RESULTS

17 pathways which Chinese cordyceps acted on seemed to be related to the anti-hypoxia effect, and "VEGF signal pathway" was one of the most important pathway. Chinese cordyceps improved the survival rate and regulated the targets related VEGF signal pathway of H9C2 cells under hypoxia, and also had significant anti-hypoxia effects to mice. Chorioallantoic membrane model experiment showed that Chinese cordyceps and the main constituents of (9Z,12Z)-octadeca-9,12-dienoic acid and cerevisterol had significant angiogenic activity in hypoxia condition.

CONCLUSION

Based on the results of network pharmacology and molecular docking analysis, cell and whole pharmacodynamic experiments, promoting angiogenesis by regulating VEGF signal pathway might be one of the mechanisms of anti-hypoxia effect of Chinese cordyceps, (9Z, 12Z)-octadeca-9,12-dienoic acid and cerevisterol were considered as the major anti-hypoxia bioactive compounds in Chinese cordyceps.

Comparative analysis of fatty acid metabolism based on transcriptome sequencing of wild and cultivated Ophiocordyceps sinensis

Background

Ophiocordyceps sinensis is a species endemic to the alpine and high-altitude areas of the Qinghai-Tibet plateau. Although O. sinensis has been cultivated since the past few years, whether cultivated O. sinensis can completely replace wild O. sinensis remains to be determined.

Methods

To explore the differences of O. sinensis grown in varied environments, we conducted morphological and transcriptomic comparisons between wild and cultivated samples who with the same genetic background.

Results

The results of morphological anatomy showed that there were significant differences between wild and cultivated O. sinensis, which were caused by different growth environments. Then, a total of 9,360 transcripts were identified using Illumina paired-end sequencing. Differential expression analysis revealed that 73.89% differentially expressed genes (DEGs) were upregulated in O. sinensis grown under natural conditions compared with that grown under artificial conditions. Functional enrichment analysis showed that some key DEGs related to fatty acid metabolism, including acyl-CoA dehydrogenase, enoyl-CoA hydratase, 3-ketoacyl-CoA thiolase, and acetyl-CoA acetyltransferase, were upregulated in wild O. sinensis. Furthermore, gas chromatography-mass spectrometry results confirmed that the fatty acid content of wild O. sinensis was significantly higher than that of cultivated O. sinensis and that unsaturated fatty acids accounted for a larger proportion.

Conclusion

These results provide a theoretical insight to the molecular regulation mechanism that causes differences between wild and cultivated O. sinensis and improving artificial breeding.

Gut Bacterial and Fungal Communities of the Wild and Laboratory-Reared Thitarodes Larvae, Host of the Chinese Medicinal Fungus Ophiocordyceps sinensis on Tibetan Plateau

Simple Summary

The ghost moth, Thitarodes sp., is an obligate host of the most precious fungus Ophiocordyceps sinensis on Tibetan plateau. Artificial rearing of the ghost moth at low-altitude laboratory by mimicking the environment of the wild habitat for the cultivation of the Chinese cordyceps has been realized. However, the high mortality of ghost moth larvae by pathogens, low and slow infection, and mummification rate by O. sinensis still constrain the efficient cultivation of the Chinese cordyceps. Both larval gut microbiota and their exploitation in the Thitarodes artificial rearing system have attracted a renewed interest. In the present study, the gut bacterial and fungal communities of the wild and laboratory-reared populations were characterized using both culture-dependent and -independent approaches. The discovery of apparent microbial community shifts between the wild and laboratory-reared ghost moth larvae, many opportunistic pathogenic bacteria and fungi in the gut of the laboratory-reared ghost moth larvae, and the dominant bacteria enriched in the wild ghost moth provide interesting cues for selecting beneficial probiotic bacteria to improve the effectiveness of Thitarodes rearing system and the cultivation of the Chinese cordyceps.

Abstract

By employing a culture-dependent and -independent 16S rRNA and ITS gene high-throughput sequencing analyses, comprehensive information was obtained on the gut bacterial and fungal communities in the ghost moth larvae of three different geographic locations from high-altitude on Tibet plateau and from low-altitude laboratory. Twenty-six culturable bacterial species belonging to 21 genera and 14 fungal species belonging to 12 genera were identified from six populations by culture-dependent method. Carnobacterium maltaromaticum was the most abundant bacterial species from both the wild and laboratory-reared larvae. The most abundant OTUs in the wild ghost moth populations were Carnobacteriaceae, Enterobacteriaceae for bacteria, and Ascomycota and Basidiomycota for fungi. Larval microbial communities of the wild ghost moth from different geographic locations were not significantly different from each other but significant difference in larval microbial community was detected between the wild and laboratory-reared ghost moth. The larval gut of the wild ghost moth was dominated by the culturable Carnobacterium. However, that of the laboratory-reared ghost moth exhibited significantly abundant Wolbachia, Rhizobium, Serratia, Pseudomonas, and Flavobacterium. Furthermore, the larval gut of the wild ghost moth had a significantly higher abundance of Ophiocordyceps but lower abundance of Candida and Aspergillus than that of the laboratory-reared ghost moth.

Toxicological safety evaluation of the cultivated Chinese cordyceps

ETHNOPHARMACOLOGICAL RELEVANCE

The Chinese cordyceps, a parasitic Thitarodes insect-Ophiocordyceps sinensis fungus complex in the Qinghai-Tibet Plateau, is one of the most valuable traditional Chinese medicines and health food for ameliorating conditions associated with aging and for treating fatigue, night sweats, hyperglycemia, hyperlipidemia, respiratory, renal and liver diseases, and hyposexuality. The natural Chinese cordyceps resource is rare due to its harsh growing environment, limited geographical distribution and global climate warming. Artificial cultivation of Chinese cordyceps has been successfully established to meet its high demand in market.

AIMS OF THE STUDY

The present study aims to evaluate the toxicological safety of the cultivated Chinese cordyceps and provide scientific data for subsequent development and utilization of this valuable biological resource.

MATERIALS AND METHODS

The Chinese cordyceps was cultivated by mimicking the habitat environment in low-altitude areas and identified by morphological and microscopic characteristics. Its phytochemical profile was determined by the HPLC. Toxicological studies based on the cultivated Chinese cordyceps were conducted, including chromosomal aberration test of Chinese hamster lung (CHL) cells, Ames test, acute toxicity test and micronucleus (MN) test of bone marrow cells.

RESULTS

The Chinese cordyceps successfully cultivated in low-altitude areas exhibited the same morphological and microscopic characteristics as natural Chinese cordyceps. The adenosine content was in accordance with the Chinese Pharmacopoeia (2015 Edition). The HPLC fingerprint was determined and five main chromatographic peaks representing uracil, uridine, inosine, guanosine and adenosine were identified. No dose-dependent increase in the rates of chromosomal aberration was detected in the presence or absence of metabolic activation system. Ames test also demonstrated no dose-dependent increase in the number of reversion mutation for five bacterial strains, with or without rat liver microsomal enzyme mixture (S9) metabolic activation, at a quantity range of 128-5000 μg cultivated Chinese cordyceps per plate. The acute toxicity test with mice showed that after 20 g/kg oral administration of cultivated Chinese cordyceps, neither animal death nor any abnormal change in general dissection of various tissues and organs of the animals were found within 14 days. The median lethal dose (LD₅₀) was greater than 5 g/kg, which is regarded as a non-toxic level, and maximum tolerable dose (MTD) of cultivated Chinese cordyceps in ICR mice was more than 20 g/kg. MN test of mouse bone marrow cells indicated no significant differences among each sample dose and the negative control.

CONCLUSION

Based on the results from four toxicological tests, it was concluded that the cultivated Chinese cordyceps was classified as non-toxic in one single administration at high doses by intragastric route in mice. This study provides scientific experimental basis for its safety.

Infection of Ophiocordyceps sinensis Fungus Causes Dramatic Changes in the Microbiota of Its Thitarodes Host

The Chinese cordyceps is a unique and valuable parasitic complex of Thitarodes/Hepialus ghost moths and the Ophiocordyceps sinensis fungus for medicine and health foods from the Tibetan Plateau. During artificial cultivation of Chinese cordyceps, the induction of blastospores into hyphae is a prerequisite for mummification of the infected Thitarodes larvae. To explore the microbial involvement in the induction of mycelia-blastospore transition, the microbiota of the hemolymph and gut from Thitarodes xiaojinensis larvae with or without injected O. sinensis blastospores were investigated by culture-dependent and -independent methods. Twenty-five culturable bacterial species and 14 fungal species, together with 537 bacterial operational taxonomic units (OTUs) and 218 fungal OTUs, were identified from the hemolymph and gut of samples from five stages including living larvae without injected fungi (A) or with high blastospore load (B), mummifying larvae without mycelia coating (C), freshly mummifying larvae coated with mycelia (D), and completely mummified larvae with mycelia (E). Two culturable bacterial species (Serratia plymuthica, Serratia proteamaculans), and 47 bacterial and 15 fungal OTUs were considered as shared species. The uninfected larval hemolymph contained 13 culturable bacterial species but no fungal species, together with 164 bacterial and 73 fungal OTUs. To our knowledge, this is the first study to detect large bacterial communities from the hemolymph of healthy insect larvae. When the living larvae contained high blastospore load, the culturable bacterial community was sharply inhibited in the hemolymph but the bacterial and fungal community greatly increased in the gut. In general, high blastospore load increased bacterial diversity but sharply decreased fungal diversity in the hemolymph and gut by OTUs. The bacterial loads of four culturable species (Chryseobacterium sp., Pseudomonas fragi, S. plymuthica, S. proteamaculans) increased significantly and O. sinensis and Pseudomonas spp. became dominant microbes, when the infected larvae became mummified, indicating their possible involvement in the larval mummification process. The discovery of many opportunistic pathogenic bacteria in the hemolymph of the healthy larvae, the larval microbial diversity influenced by O. sinensis challenge and the involvement of dominant bacteria during larval mummification process provide new insight into the infection and mummification mechanisms of O. sinensis in its Thitarodes hosts.

Targeting NLRP3 inflammasome as a promising approach for treatment of diabetic nephropathy: Preclinical evidences with therapeutic approaches

Diabetes mellitus is an increasingly prevalent disease around the globe. The epidemic of diabetes mellitus and its complications pretenses the foremost health threat globally. Diabetic nephropathy is the notable complication in diabetes, leading to end-stage renal disease (ESRD) and premature death. Abundant experimental evidence indicates that oxidative stress and inflammation are the important mediators in diabetic kidney diseases and interlinked with various signal transduction molecular mechanisms. Inflammasomes are the critical components of innate immunity and are recognized as a critical mediator of inflammation and autoimmune disorders. NOD-like receptor protein 3 (NLRP3) inflammasome is the well-characterized protein and it exhibits the sterile inflammation through the regulation of pro-inflammatory cytokines interleukin (IL)-1β and IL-18 production in tissues. In recent years, the role of NLRP3 inflammasome in the pathophysiology of diabetic kidney diseases in both clinical and experimental studies has generated great interest. In the current review, we focused on and discussed the role of NLRP3 inflammasome in diabetic nephropathy. A literature review was performed using online databases namely, PubMed, Scopus, Google Scholar and Web of science to explore the possible pharmacological interventions that blunt the NLRP3 inflammasome-caspase-1-IL-1β/IL-18 axis and shown to have a beneficial effect in diabetic kidney diseases. This review describes the inhibition of NLRP3 inflammasome activation as a promising therapeutic target for drug discovery in future.

Policies and Problems of Modernizing Ethnomedicine in China: A Focus on the Yi and Dai Traditional Medicines of Yunnan Province

Yunnan is a multiethnic province in southwest China, rich in Materia medica resources, and is popularly known as the kingdom of plants. Biomedicine and public health industry have been the industrial pillars of Yunnan since 2016, which is the important pharmaceutical industrial base for Dai and Yi medicine in China. This review of the Yunnan ethnic medicine industry describes some of the problems to be solved in the development of sustainable ethnomedicine in China. We investigated Chinese patent medicines (CPMs) declared as ethnomedicine on the drug instructions and identified 28 Dai patent medicines (DPMs) and 73 Yi patent medicines (YPMs) that were approved for clinical use in China. In further research, the clinical indications of these CPMs were determined, and the quality standard of medicinal materials and their usage frequencies in DPMs and YPMs were investigated. We also collected and analyzed the data on use of botanical and animal sources of medicines, the rare and endangered medicinal materials, and toxic medicines in DPMs and YPMs. The application of zootherapy in Yi traditional medicine was introduced from its abundant ancient documents and records; based on the "YaGei" theory in Dai traditional medicine, toxic medicines can be relatively safe in DPMs. However, for promoting the Yunnan traditional medicine industry, it is necessary to strengthen medical research to expand evidence-based clinical practice and balance ethnomedicine production and sustainable utilization of Materia medica resources, especially the animal sources of medicines, toxic medicines, and the protected wild resources reported in this survey. Only in this way can industrialization of ethnomedicine promote the improvement of human health.

Report on the Emergence Time of a Species of Thitarodes Ghost Moth (Lepidoptera: Hepialidae), Host of the Caterpillar Fungus Ophiocordyceps sinensis (Ascomycota: Ophiocordycipitaceae) in Uttarakhand, India

Ghost moths in the genus Thitarodes Viette, 1968, are hosts of the economically important caterpillar fungus, which is harvested in high mountain meadows across the Hengduan mountains and the Himalayas. In northwestern India, although caterpillar fungus has been collected in the state of Uttarakhand, no adults of Thitarodes species have been recorded. We report the sighting of a female pupa of Thitarodes sp. and its last-instar molt at Munsiyari, Uttarakhand, India, on 5 July 2019 and estimate that the adult emergence time in this habitat should be late July or early August. Although the habitats of caterpillar fungus in Uttarakhand are geographically closer to those in Nepal, they are climatically more similar to habitats of caterpillar fungus in Qinghai province in China. Among records at the same elevation, climatic variables are highly predictive of the emergence date of Thitarodes adults (adjusted-R2: 0.7925, F = 6.27, P = 0.03). Our result highlights the role of the Himalayan mountains as both a north-south climatic barrier and an east-west climatic gradient. We encourage local stakeholders and scientists in Uttarakhand to survey adult emergences of Thitarodes from July to mid-August.

Quorum Sensing Activity and Hyphal Growth by External Stimuli in the Entomopathogenic Fungus Ophiocordyceps sinensis

The entomopathogenic fungus Ophiocordyceps sinensis is one of the best known and most precious medicines and health food in China. The blastospores-hyphae (dimorphism) transition of this fungus in host hemolymph is critical for the virulence and the mummification of host larvae. To regulate this transition, the effects of inoculum density and fifteen chemicals including fungal nutrients, fungal metabolites, quorum-sensing molecules (QSMs) and insect hormones on the dimorphism in O. sinensis were investigated in vitro. The blastospores tended to exhibit budding growth when inoculated at 10⁷ blastospores per mL, and hyphal growth at concentrations lower than 10⁶ blastospores per mL. At 10⁵ blastospores per mL, the percentage of hyphal formation decreased with the addition of filtered spent medium containing 10⁷ blastospores per mL, indicating the quorum-sensing effect. Blastospores-hyphae transition in this fungus by fifteen chemicals was varied from no response to dimorphic reversion. The addition of N-acetylglucosamine at three concentrations significantly stimulated hyphal formation while inhibiting budding growth. For the first time, insect hormone 20-hydroxyecdysone was found to be involved in the hyphal formation in fungi. These results open new possibilities to regulate the dimorphism, which would be beneficial for the cultivation of the Chinese cordyceps.

Biogenesis of macrofungal sclerotia: influencing factors and molecular mechanisms

Sclerotia are dense, hard tissue structures formed by asexual reproduction of fungal hyphae in adverse environmental conditions. Macrofungal sclerotia are used in medicinal materials, healthcare foods, and nutritional supplements because of their nutritional value and biologically active ingredients, which are attracting increasing attention. Over the past few decades, the influence of abiotic factors such as nutrition (e.g., carbon and nitrogen sources) and environmental conditions (e.g., temperature, pH), and of the local biotic community (e.g., concomitants) on the formation of macrofungal sclerotia has been studied. The molecular mechanisms controlling macrofungal sclerotia formation, including oxidative stress (reactive oxygen species), signal transduction (Ca²⁺ channels and mitogen-activated protein kinase pathways), and gene expression regulation (differential expression of important enzyme or structural protein genes), have also been revealed. At the end of this review, future research prospects in the field of biogenesis of macrofungal sclerotia are discussed. KEY POINTS: • We describe factors that influence biogenesis of macrofungal sclerotia. • We explain molecular mechanisms of sclerotial biogenesis. • We discuss future directions of study of macrofungal sclerotia biogenesis.

Comparative Transcriptome Analysis of Thitarodes Armoricanus in Response to the Entomopathogenic Fungi Paecilomyces Hepiali and Ophiocordyceps Sinensis

Thitarodes armoricanus is a medicinal and economically important Lepidopteran insect species. The larvae infected by Paecilomyces hepiali survive no more than four days, while those infected by Ophiocordyceps sinensis can survive for several months before mummification. This provides a valuable comparative system to study interactions between an insect host and different pathogenic fungi. By using the T. armoricanus genome, a time-course transcriptome analysis of the whole larvae without guts was performed to explore the larvae response to P. hepiali and O. sinensis infection. A total of 3106 differentially expressed genes in five clusters were identified. The genes involved in coagulation and multiple metabolisms were both suppressed after P. hepiali or O. sinensis infection, whereas those related to environmental information responses, cell processes, biotic stimulus, and immunity (such as cecropin (CEC)) were elevated. The rapid death of T. armoricanus after P. hepiali infection might be caused by osmotic imbalance, immunocompromise (such as DEFs and GLVs), and nervous system dysfunction (glutamatergic synapse). Up-regulation of the genes related to cuticle structure, nervous system (such as neurotrophin signal pathway and dopaminergic synapse) and immune effectors (such as attacin (ATT) and proline-rich antimicrobial peptide 1 (PRAMP1)) in T. armoricanus, may contribute to the co-existence of T. armoricanus and O. sinensis. This study provides a global view and potential key genes of the interaction between T. armoricanus and two fungal entomopathogens.

Artificial Cultivation of the Chinese Cordyceps From Injected Ghost Moth Larvae

The Chinese cordyceps, regarded as the 'Himalayan Viagra', is highly valued for its medicinal benefits. The decline of its yield due to over-exploitation and increased market demand have stimulated efforts to artificially cultivate Chinese cordyceps for over half a century. However, successful cultivation of Chinese cordyceps through caterpillar infection by the fungus Ophiocordyceps sinensis (Berk.) and the induction of the fruiting body from each mummified cadaver remains difficult for its complex life cycle. Herein, we report the developmental dynamics of hyphal bodies in hemolymph of injected Thitarodes xiaojinensis (Tu, Ma & Zhang) larvae and the success in artificial cultivation of sexual fruiting bodies from the mummified cadavers in the low-altitude area. We find that not only the numbers of hyphal bodies but also the conversion of hyphal bodies into hyphae played important roles in the mummification of the injected larvae. This cultivation will be beneficial for sustainable utilization of natural resources and provides the possibility for further research on the mechanism of the interaction between pathogenic fungus and host insect.

Diversity and Co-Occurrence Patterns of Soil Bacterial and Fungal Communities of Chinese Cordyceps Habitats at Shergyla Mountain, Tibet: Implications for the Occurrence

Chinese Cordyceps is a well-known medicinal larva-fungus symbiote distributed in the Qinghai-Tibetan Plateau and adjacent areas. Previous studies have involved its artificial cultivation but commercial cultivation is difficult to perform because the crucial factors triggering the occurrence of Chinese Cordyceps are not quite clear. The occurrence of Chinese Cordyceps is greatly affected by the soil environment, including the soil’s physicochemical and microecological properties. In this study, the effects of these soil properties on the occurrence of Chinese Cordyceps were investigated. The results show that the physicochemical properties, including easily oxidizable organic carbon (EOC), soil organic carbon (SOC), humic acid carbon (HAC), humin carbon (HMC), and pH, might be negatively related to the occurrence of Chinese Cordyceps, and soil water content (SWC) might be positively related. Several soil physicochemical parameters (pH, SOC, HMC, HAC, available potassium (APO), available phosphorus (APH), microbial biomass carbon (MBC), and the ratio of NH₄⁺ to NO₃⁻ (NH₄⁺/NO₃⁻)) and microbial properties interact and mix together, which might affect the occurrence of Chinese Cordyceps. Soil microbial community structure was also a possible factor, and a low level of bacterial and fungal diversity was suitable for the occurrence of Chinese Cordyceps. The intra-kingdom network revealed that a closer correlation of the bacterial community might help the occurrence of Chinese Cordyceps, while a closer correlation of the fungal community might suppress it. The inter-kingdom network revealed that the occurrence rate of Chinese Cordyceps might be negatively correlated with the stability of the correlation state of the soil habitat. In conclusion, this study shows that soil physicochemical properties and microbial communities could be greatly related with the occurrence of Chinese Cordyceps. In addition, soil physicochemical properties, the level of bacterial and fungal diversity, and correlations of bacterial and fungal communities should be controlled to a certain level to increase the production of Chinese Cordyceps in artificial cultivation.

Characterization of Humic Substances in the Soils of Ophiocordyceps sinensis Habitats in the Sejila Mountain, Tibet: Implication for the Food Source of Thitarodes Larvae

Humic substances in soil are considered to be an alternative food to the tender plant roots for Thitarodes larvae in the habitats of Ophiocordyceps sinensis in the Qinghai-Tibetan Plateau. However, there is no report involving the evaluation of their potential as a food source from the composition and structure of habitat soils. In this work, the composition and structure of humic substances in habitat soils from the Sejila Mountain, Tibet were characterized by diverse techniques for evaluating the nutritional value and possibility of humus as the food source for Thitarodes larvae. Fourier transform infrared spectroscopy revealed that humic acid may possess superior ability to provide the molecular segments for biosynthesizing lipids more than other humic fractions. Combining with the analysis of solid-state 13C nuclear magnetic resonance spectrum, the fractions of hydrophobic fulvic acid and hydrophilic fulvic acid are further considered as a potential food source for Thitarodes larvae. Overall, humic substances in habitat soils are rich in the molecular segments for biosynthesizing lipids and other important nutrients, which may provide the energy and material sources for maintaining the survival of Thitarodes larvae in the absence of tender plant roots, particularly in the annual cold winter. Combining with the evidence of physico-chemical parameters of habitat soils and stable carbon isotopic composition of major tender plant roots in the Sejila Mountain, the composition and structure of humic substances in habitat soils may provide a novel idea for the eco-friendly and semi-wild cultivation of Thitarodes larvae with low cost.

Comparative transcriptome analysis reveals molecular strategies of ghost moth Thitarodes armoricanus in response to hypoxia and anoxia

Hypoxia or anoxia greatly impact the survival of many animal species. The ghost moth Thitarodes armoricanus is distributed in the Tibetan Plateau at an average elevation of approximate 4 km above sea level and has probably evolved a superior capacity to tolerate low oxygen levels. In this study, transcriptome analysis using high-throughput RNA-seq revealed common and different adaptation strategies of T. armoricanus in response to hypoxia (11% O₂) or anoxia. T. armoricanus adopted three common strategies for adaptation to hypoxia or anoxia: Up-regulated signal transduction pathways essential for cellular survival, strengthened cell and organelle structure and activity, and activated immune system. Under hypoxia, T. armoricanus might develop a strategy to adapt to hypoxia by suppressing TCA, oxidative phosphorylation pathways, and hypoxanthine catabolism. T. armoricanus larvae kept active under hypoxia but became coma under anoxia, probably relating to up-regulated or suppressed dopamine synthesis pathway. Furthermore, the HIF system seemed not to be essential for regulating the hypoxic and anoxic responses of this insect in Tibetan Plateau. This study provides a global view of gene expression profiles and suggests common and different adaptation strategies of T. armoricanus under hypoxic and anoxic conditions. The results are helpful for understanding the mechanism responsible for the low oxygen level tolerance of this insect species.

A breakthrough in the artificial cultivation of Chinese cordyceps on a large-scale and its impact on science, the economy, and industry

Chinese cordyceps, an entity of the Chinese caterpillar fungus (Ophiocordyceps sinensis, syn. Cordyceps sinensis) that parasitizes ghost moth larvae, is one of the best known traditional Chinese medicines and is found exclusively on the Tibetan Plateau with limited natural resources. Although the fungus O. sinensis can grow on artificial substrates and the ghost moth has been successfully reared, the large-scale artificial cultivation of Chinese cordyceps has only recently been accomplished after several decades of efforts and attempts. In this article, research progress related to this breakthrough from living habitats, the life history of the fungus, its host insect, fungal isolation and culture, host larvae rearing, infection cycle of the fungus to the host, primordium induction, and fruiting body development have been reviewed. An understanding of the basic biology of O. sinensis, its host insect and the simulation of the Tibetan alpine environment resulted in the success of artificial cultivation on a large scale. Practical workshop production has reached annual yields of 2.5, 5, and 10 tons in 2014, 2015, and 2016, respectively. There was no difference in the chemical components detected between the cultivated and natural Chinese cordyceps. However, the artificial cultivation system can be controlled to avoid heavy metal contamination and results in high-quality products. Although omics studies, including genomic, transcriptomic, proteomic, and metabolomic studies, have helped to understand the biology of the fungus, the success of the artificial cultivation of the Chinese cordyceps is clearly a milestone and provides the possibility for research on the in-depth mechanisms of the interaction between the fungus and host insects and their adaptation to the harsh habitats. This cultivation will not only result in a large industry to alleviate the pressure of human demand but also protect the limited natural resources for sustainable utilization.

Discriminatory Power Evaluation of Nuclear Ribosomal RNA Barcoding Sequences Through Ophiocordyceps sinensis Related Samples

Since the cost of Ophiocordyceps sinensis has increased dramatically and the counterfeits may have adverse effect to health, a rapid and precise species-level DNA barcoding identification system could be a potent approach and significantly enhance the regulatory capacity. The discrimination power of three subunits sequences from nuclear ribosomal RNA gene cluster were determined by Simpson’s index of discrimination using 43 wild O. sinensis fruiting bodies, pure cultures, commercial mycelium fermented powder and counterfeits. The internal transcribed spacer (ITS) sequences showed the highest variance and discrimination power among 43 samples, as determined by Simpson’s index of discrimination (D = 0.972), followed by large subunit (LSU; D = 0.963) and small subunit (SSU; D = 0.921). ITS-2 sequences showed the highest discrimination power for 43 samples among ITS-1, ITS-2, and 5.8S region of ITS sequences. All O. sinensis samples were grouped into a unique ITS sequence cluster under 95% similarity and two O. sinensis samples and six non-O. sinensis samples showed false claims. Our data showed that the ITS region could provide accurate species identification for O. sinensis samples, especially when macroscopic and microscopic method could not be applied in the highly processed commercial products. Since the authentication of O. sinensis related products is essential to ensure its safety and efficacy, identification of O. sinensis through ITS sequence comparison or unique PCR amplification of the species specific target, such as the ITS region, should be considered in the next revision of Chinese pharmacopeia.

Discovery of differential sequences for improving breeding and yield of cultivated Ophiocordyceps sinensis through ITS sequencing and phylogenetic analysis

To accelerate the breeding process of cultivated Ophiocordyceps sinensis and increase its yield, it is important to identify molecular fingerprint of dominant O. sinensis. In the present study, we collected 3 batches of industrially cultivated O. sinensis product with higher yield than the others and compared their internal transcribed spacer (ITS) sequences with the wild and the reported. The ITS sequence was obtained by bidirectional sequencing and analyzed with molecular systematics as a DNA barcode for rapid and accurate identification of wild and cultivated O. sinensis collected. The ITS sequences of O. sinensis with detailed collection loci on NCBI were downloaded to construct a phylogenetic tree together with the sequences obtained from the present study by using neighbor-joining method based on their evolution relationship. The information on collection loci was analyzed with ArcGIS 10.2 to demonstrate the geographic distribution of these samples and thus to determine the origin of the dominant samples. The results showed that all wild and cultivated samples were identified as O. sinensis and all sequences were divided into seven phylogenetic groups in the tree. Those groups were precisely distributed on the map and the process of their system evolution was clearly presented. The three cultivated samples were clustered into two dominant groups, showing the correlation between the industrially cultivated samples and the dominant wild samples, which can provide references for its optimized breeding in the future.

Metabolomic comparison between wild Ophiocordyceps sinensis and artificial cultured Cordyceps militaris

A systematic study on the metabolome differences between wild Ophiocordyceps sinensis and artificial cultured Cordyceps militaris was conducted using liquid chromatography-mass spectrometry. Principal component analysis and orthogonal projection on latent structure-discriminant analysis results showed that C. militaris grown on solid rice medium (R-CM) and C. militaris grown on tussah pupa (T-CM) evidently separated and individually separated from wild O. sinensis, indicating metabolome difference among wild O. sinensis, R-CM and T-CM. The metabolome differences between R-CM and T-CM indicated that C. militaris could accommodate to culture medium by differential metabolic regulation. Hierarchical clustering analysis was further performed to cluster the differential metabolites and samples based on their metabolic similarity. The higher content of amino acids (pyroglutamic acid, glutamic acid, histidine, phenylalanine and arginine), unsaturated fatty acid (linolenic acid and linoleic acid), peptides, mannitol, adenosine and succinoadenosine in O. sinensis make it as an excellent choice as a traditional Chinese medicine for invigoration or nutritional supplementation. Similar compositions with O. sinensis and easy cultivation make artificially cultured C. militaris a possible alternative to O. sinensis.

Identification of Ophiocordyceps sinensis and Its Artificially Cultured Ophiocordyceps Mycelia by Ultra-Performance Liquid Chromatography/Orbitrap Fusion Mass Spectrometry and Chemometrics

Since the cost of Ophiocordyceps sinensis, an important fungal drug used in Chinese medicine, has increased dramatically, and the counterfeits may have adverse health effects, a rapid and precise marker using the peptide mass spectrometry identification system could significantly enhance the regulatory capacity. In this study, we determined the marker peptides in the digested mixtures of fungal proteins in wild O. sinensis fruiting bodies and various commercially available mycelium fermented powders using ultra-performance liquid chromatography/Orbitrap Fusion mass spectrometry coupled with chemometrics. The results indicated the following marker peptides: TLLEAIDSIEPPK (m/z 713.39) was identified in the wild O. sinensis fruiting body, AVLSDAITLVR (m/z 579.34) was detected in the fermented O. sinensis mycelium powder, FAELLEK (m/z 849.47) was found in the fermented Ophiocordyceps mycelium powder, LESVVTSFTK (m/z 555.80) was discovered in the artificial Ophiocordyceps mycelium powder, and VPSSAVLR (m/z 414.75) was observed in O. mortierella mycelium powder. In order to verify the specificity and applicability of the method, the five marker peptides were synthesized and tested on all samples. All in all, to the best of our knowledge, this is the first time that mass spectrometry has been employed to detect the marker peptides of O.sinensis and its related products.

Artificially Cultivated Ophiocordyceps sinensis Alleviates Diabetic Nephropathy and Its Podocyte Injury via Inhibiting P2X7R Expression and NLRP3 Inflammasome Activation

BACKGROUND/AIMS

It is known that chronic low-grade inflammation contributes to the initiation and development of both diabetes and diabetic nephropathy (DN), so we designed this study to investigate the role of P2X7R and NLRP3 inflammasome in DN pathogenesis and the antagonistic effects of artificially cultivated Ophiocordyceps sinensis (ACOS).

METHODS

A rat model of DN caused by high-fat-diet feeding and low-dose streptozotocin injection and a mouse podocyte injury model induced by high-glucose (HG) stimulation were established, and the intervention effects of ACOS on them were observed. The biological parameters of serum and urine and the pathological manifestations of kidney tissue were examined. The expression of mRNA and protein of P2X7R and NLRP3 inflammasome (NLRP3, ASC, and caspase-1) and downstream effectors (IL-1β and IL-18), as well as podocyte-associated molecules, was determined by real-time quantitative PCR and Western blot assay, respectively.

RESULTS

The DN rats showed to have developed insulin resistance, elevated fasting blood glucose, increased urinary protein excretion, and serum creatinine level as well as corresponding glomerular pathological alterations including podocyte damages. ACOS significantly antagonized the above changes. The experiments in vivo and in vitro both displayed that the mRNA and protein expression of P2X7R, NLRP3, ASC, caspase1 (procaspase-1 mRNA in the gene level and active caspase-1 subunit P10 in the protein level), IL-1β, and IL-18 was significantly upregulated and the mRNA and protein expression of podocyte-associated molecules was significantly changed (downregulation of nephrin, podocin, and WT-1 expression and upregulation of desmin expression) indicating podocyte injury in the kidney tissue of DN rats and in the HG-stressed mouse podocytes, respectively. ACOS also significantly antagonized all the above changes.

CONCLUSION

Our research work suggests that P2X7R and NLRP3 inflammasome are involved in the pathogenesis of DN, and ACOS can effectively inhibit the high expression of P2X7R and the activation of NLRP3 inflammasome, which may contribute to the therapeutic effects of Ophiocordyceps sinensis.

Stable Carbon Isotope Composition of the Lipids in Natural Ophiocordyceps sinensis from Major Habitats in China and Its Substitutes

Ophiocordyceps sinensis is one rare medicinal fungus produced in the Qinghai-Tibetan Plateau. Its quality and price varies hugely with different habitat, and its numerous substitutes have sprung up in functional food markets. This paper aims to discriminate the geographic origin of wild O. sinensis and its substitutes via element analyzer-isotope ratio mass spectrometry and gas chromatography-isotope ratio mass spectrometry. The δ13C values of major fatty acids in the lipids of O. sinensis are characterized unanimously by the variation relation C18:0 < C18:2 ≈ C16:0 < C18:1, while their fluctuation intervals are notably different between those of neutral and polar lipids. The comparative analysis of the δ13C ratios of major fatty acids in lipids of O. sinensis suggests that the δ13C patterns may be sensitive potential indicators to discriminate its geographical origin. The δ13C values of individual major fatty acids of lipids from the cultivated stromata of Cordyceps militaris (SCM), the fermented mycelia of Hirsurella sinensis (FMH) and Paecilomyces epiali (FMP) range from -31.2‰ to -29.7‰, -16.9‰ to -14.3‰, and -26.5‰ to -23.9‰, respectively. Their δ13C pattern of individual major fatty acids may be used as a potential indicator to discriminate the products of natural O. sinensis and its substitutes.

Fungus-larva relation in the formation of Cordyceps sinensis as revealed by stable carbon isotope analysis

For more than one thousand years, Cordyceps sinensis has been revered as a unique halidom in the Qinghai-Tibetan Plateau for its mysterious life history and predominant medicinal values. This mysterious fungus-larva symbiote also attracted the over-exploitation, while several problems on the initial colonization of Ophiocordyceps sinensis in the host larva have constrained artificial cultivation. In this work, stable carbon isotope analysis was employed to analyse the subsamples of C. sinensis from 5 representative habitats. The results demonstrated that these samples possessed similar δ¹³C profiles, i.e., a steady ascending trend from the top to the bottom of stroma, occurrence of the δ¹³C maximum at the head, a slight decrease from the head to the end of thorax, a sharply descent trend from the end of thorax to the forepart of abdomen, and maintenance of lower δ¹³C values in the rest parts of abdomen. Based on the data, we consider that the site near the head of the host larva may be the initial target attacked by O. sinensis, and the fungus growth is closely related to the digestive tract of its host larva. The growth stages of O. sinensis are accordingly speculated as the symptom-free, symptom-appearing, and stroma-germinating stages.

Profiling metals in Cordyceps sinensis by using inductively coupled plasma mass spectrometry

Cordyceps sinensis (C. sinensis) is a natural product that has diverse nutritional and medicinal values. Since the availability of natural C. sinensis becomes limited its authentication and quality control is of high significance. Herein we report on profiling of metals in C. sinensis by using inductively coupled plasma mass spectrometry (ICP-MS). The analysis reveals that C. sinensis contains a wide array of essential elements, including P, Mg, Zn, Cu, Fe, etc. Toxic metals detected are Cd, Pb, and As. In all five samples analyzed Pb contents are below 2.0 ppm. Arsenic level in C. sinensis caterpillar is significantly higher than that in its mycelium and varies from 3.0 to 32 ppm likely due to soil contamination. It's for the first time demonstrated in this work that clustering analysis on the proposed metal profiles consisting of 24 elements is very useful to identify "abnormal" C. sinensis samples, thus adding another dimension to the effective means for authentication and quality assessment of this highly demanded previous natural product.

The mitochondrial genome of the lepidopteran host cadaver (Thitarodes sp.) of Ophiocordyceps sinensis and related phylogenetic analysis

To understand the phylogeny of the host insect (Thitarodes sp.) of the fungus Ophiocordyceps sinensis, we sequenced, annotated and characterized the complete mitochondrial (mt) genome of the host cadaver of a natural O. sinensis. Further, we compared the Thitarodes sp. mt genome with those of the other 7 sequenced Hepialidae and examined the phylogenetic relationships using a constructed Maximum Likelihood (ML) phylogenetic tree and mt genomic features (genetic distances and intergenic spacers). The mt genome is a circular molecule of 16,280bp in length with a high A+T content (81.20%) and contains 13 protein-coding genes (PCGs), 2 rRNA genes, 22 tRNA genes and an AT-rich region. The gene arrangement is identical to the ancestral arrangement but differs from those of other lepidopteran mt genomes because of the arrangement of tRNA genes. The tRNA region, which is located between the AT-rich region and nad2, is trnI/trnQ/trnM (IQM) in Thitarodes sp., rather than the trnM/trnI/trnQ (MIQ) of the Lepidoptera-specific rearrangement. All PCGs begin with the canonical start codons ATN or NTG, except for cox1, which starts with CGA. Most PCGs terminate with the typical stop codon TAA, although some have an incomplete stop codon (T). The 1473bp AT-rich region is located between the rrnS (12S rRNA) and trnI, which is the longest sequenced in a Thitarodes mt genome to date, containing nine 112bp copies and one partial copy of a 55bp sequence. The results derived from the phylogenetic tree, the genetic distances and the intergenic spacers of the mt genome show that the host insect of O. sinensis belongs to the Thitarodes, while Endoclita signifer and Napialus hunanensis form a relatively distinct lineage from Thitarodes. The sequence and full annotation of this moth mt genome will provide more molecular information about the Exoporia within the Lepidoptera, and the clarification of its phylogeny will improve the management of this insect resource and the conservation and sustainable use of this endangered medicinal species in China.

Dual-Directional Immunomodulatory Effects of Corbrin Capsule on Autoimmune Thyroid Diseases

Purpose. To investigate the effects of Corbrin Capsule (CS-C-Q80), a drug derived from Cordyceps sinensis (Berk.) Sacc., on autoimmune thyroid diseases (AITD). Methods. 44 Patients with Graves's disease (GD) and 56 patients with Hashimoto's thyroiditis (HT) were randomly assigned to treatment group (GD-Tx and HT-Tx) or control group (GD-Ct and HT-Ct). The control groups were given methimazole or levothyroxine only while the treatment groups were given Corbrin Capsule (2.0 g tid) besides the same conventional prescriptions as control groups. Thyroid hormones, thyroid antibodies, and T lymphocyte subsets were quantified at baseline and 24 weeks posttreatment. Results. Significant drop of serum anti-TPO-Ab levels was observed in both GD-Tx and HT-Tx groups. Before treatment, GD patients had higher helper T cells compared to cytotoxic T cells, while HT patients suffered from a nearly inverted proportion of helper T/cytotoxic T cells. There was a significant drop of the helper T/cytotoxic T cells ratio in GD-Tx to the median of the normal ranges after Corbrin treatment for 24 weeks, while that in HT-Tx was elevated. Conclusion. Corbrin Capsule could restore the balance between helper T and cytotoxic T cells in both GD and HT patients with dual-directional immunomodulatory effects. And it could significantly reduce the autoantibody levels in both GD and HT.

High-throughput sequencing-based analysis of endogenetic fungal communities inhabiting the Chinese Cordyceps reveals unexpectedly high fungal diversity

Chinese Cordyceps, known in Chinese as “DongChong XiaCao”, is a parasitic complex of a fungus (Ophiocordyceps sinensis) and a caterpillar. The current study explored the endogenetic fungal communities inhabiting Chinese Cordyceps. Samples were collected from five different geographical regions of Qinghai and Tibet, and the nuclear ribosomal internal transcribed spacer-1 sequences from each sample were obtained using Illumina high-throughput sequencing. The results showed that Ascomycota was the dominant fungal phylum in Chinese Cordyceps and its soil microhabitat from different sampling regions. Among the Ascomycota, 65 genera were identified, and the abundant operational taxonomic units showed the strongest sequence similarity to Ophiocordyceps, Verticillium, Pseudallescheria, Candida and Ilyonectria Not surprisingly, the genus Ophiocordyceps was the largest among the fungal communities identified in the fruiting bodies and external mycelial cortices of Chinese Cordyceps. In addition, fungal communities in the soil microhabitats were clustered separately from the external mycelial cortices and fruiting bodies of Chinese Cordyceps from different sampling regions. There was no significant structural difference in the fungal communities between the fruiting bodies and external mycelial cortices of Chinese Cordyceps. This study revealed an unexpectedly high diversity of fungal communities inhabiting the Chinese Cordyceps and its microhabitats.

Pyrosequencing analysis revealed complex endogenetic microorganism community from natural DongChong XiaCao and its microhabitat

BACKGROUND

Ophiocordyceps sinensis (DongChong XiaCao (DCXC) in Chinese), a fungal parasite of caterpillars, is a traditional Chinese medicine. Bioactive components isolated from natural DCXC possess a wide range of pharmacological actions. Many efforts have been directed towards isolating the fungi based on culture-dependent methods for investigation of fungal diversity in order to determine the anamorph of natural DCXC and find new medicinal fungi resources, and the results have been varied.

RESULTS

In the present study, a total of 44,588 bacterial and 51,584 fungal sequences corresponding to 11,694 and 9297 putative operational taxonomic units (OTU) were respectively identified by a Roche/454-based, high throughput sequence analysis of 16S rRNA genes and ITS regions. The main bacterial groups were Proteobacteria, Acidobacteria, Bacteroidetes, Actinobacteria and Firmicutes, while the Ascomycota, Basidiomycota and Zygomycota were the main fungal phyla. Proteobacteria presented 68.4, 49.5, 38.9 and 35.6 % of all bacteria in the sclerotia, stromata, external mycelial cortices and soil, respectively. As the main fungi phyla, Ascomycota presented 21.0, 45.6 26.4 and 59.3 % in the sclerotia, stromata, external mycelial cortices and soil, respectively. Bacterial and fungal communities were more diverse in the environmental sample than in the natural DCXC sample. Microbial communities were obviously distinct in each sample. Several novel unclassifiable bacterial (10.41 %) and fungal (37.92 %) species were also detected.

CONCLUSIONS

This study revealed an abundant endogenetic fungal and bacterial resources and a variety of genetic information in natural DCXC by high-throughput 454 sequencing technology. Microorganism that had been discovered in natural DCXC will provide sources for screening the new bioactive metabolites and its biotechnological application.

Evaluation of Reference Genes for Reverse Transcription Quantitative PCR Studies of Physiological Responses in the Ghost Moth, Thitarodes armoricanus (Lepidoptera, Hepialidae)

Reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) is the sensitive method to quantify the expression levels of target genes on the basis of endogenous control. An appropriate reference gene set for normalization is essential for reliable results. The ghost moth, Thitarodes armoricanus, a host species of a medicinal fungus, Ophiocordyceps sinensis, is an economically important member of the Lepidoptera. Recent studies have focused on the mechanism of adaptation of this species to its high-altitude environment and host immune response to O. sinensis infection and RT-qPCR is commonly used in these studies to decipher the genetic basis of physiological functions. However, a thorough assessment of candidate reference genes in the genus Thitarodes is lacking. Here, the expression levels of eight candidate reference genes (ACT, EF, EIF4A, GAPDH, G6PDH, RPL13A, TUB and 18S) in T. armoricanus at different developmental stages and in different body parts of the seventh instar larvae were analyzed, along with larvae kept under low temperatures, larvae exposed to two fungal infections and larvae fed different diets. Three established software programs–Bestkeeper, geNorm and NormFinder–were employed to calculate variation among the treatments. The results revealed that the best-suited reference genes differed across the treatments, with EF, EIF4A and GAPDH found to be the best suited for the different developmental stages and larvae body parts; EF, EIF4A and RPL13A found to be the best suited for low-temperature challenge; and EF, EIF4A and TUB found to be the best suited for the fungal infections and dietary treatments. This study thus further contributes to the establishment of an accurate method for normalizing RT-qPCR results for T. armoricanus and serves as a reference for gene expression studies of related insect species.